Method of and apparatus for improving the operation of an engine

ABSTRACT

A method for improving the operation of an engine including a cylinder space, a piston movable therein, at least one inlet valve having an inlet duct associated therewith, and at least one outlet valve having an outlet duct associated therewith includes providing an air filling in the inlet duct upstream of the inlet valve(s). An initial portion of the air filling is introduced into the cylinder space while the outlet valve(s) is open, whereby the initial portion of air filling flushes the cylinder space and exits into the outlet duct through the open outlet valve(s). Upon closing of the outlet valve(s) the introduction of the air filling into the cylinder space is continued and thereafter an air-and-fuel mixture is brought into the cylinder space through the same inlet duct(s) and inlet valve(s) through which the air filling has passed in being introduced into the cylinder, resulting in a fuel charge stratified a top of the retained air filling.

FIELD OF THE INVENTION

The present invention relates to a method of improving the operation ofan engine and to an apparatus for carrying out the method.

BACKGROUND OF THE INVENTION

A drawback with engines used at present is that some of the gasesalready burned during the preceding power stroke remain in the cylinderspace, which is liable to impair efficiency since there is no combustionof gases already burned. Furthermore, during the flushing of a cylinderspace, some of the fuel-and-air mixture may find its way into theexhaust manifold which causes an increase in the consumption of fuel.

One solution for improving the operation of an internal combustionengine is disclosed in the publication DE-OS 19 20 751. This publicationdescribes an apparatus for preventing the passage of fuel-and-airmixture through the outlet valve into the outlet duct during aninduction stroke. The apparatus includes an air pipe, which is fitted inthe intake manifold and from which branches an air duct to the base ofeach inlet valve. The air issuing from this air duct provides a flushingeffect as the inlet valve and outlet valve are simultaneously open.However, the apparatus disclosed in the above publication isconstructionally unreliable in providing a satisfactory flushing action.In addition, the cited publication does not take into consideration allpossiblities for the operation of an engine achieved by means of airfilling or the like.

The following is a list of the most essential features in terms of theoperation of an engine for the passage of fuel-air-air-mixture:

The burned gases must be removed as thoroughly as possible from thecylinder space prior to passing a fuel-and-air mixture into the cylinderspace

during the flushing no fuel-and-air mixture can be allowed to pass intothe exhaust pipe,

filling of the cylinder space must be as complete as possible regardlessof the running speed,

the simultaneous open condition or overlap results in increased fillingand thus increased power,

cooling of the valves and cylinders by means of air increases thefilling. In theory, this can be derived from the equation

    ΔV=δ·V.sub.0 ·Δt

In the equation, V₀ is the volume of gas at 0° C. and the magnitude ofcoefficient δ is 1/273° C.⁻¹. This leads to a conclusion that, whenheated to 273° C., the volume of gas expands to double, and

the complete combustion of fuel with excess air produces cleaner exhaustgases. This decreases especially the amount of the oxides of nitrogen.

SUMMARY OF THE INVENTION

An object of the invention is to provide a solution for achieving theabove-mentioned properties and at the same time for eliminating thedrawbacks of the prior art. In order to achieve this object, a method ofthe invention is essentially characterized in that an air filling or thelike is introduced into an inlet duct or the like prior to the start ofan induction stroke in a manner that the air filling is first in theinlet duct immediately upstream of an inlet valve and that at least someof the air filling or the like is introduced into the cylinder spacewhile the outlet valve is closed.

Thus, it is possible, although not necessary, that a method disclosed inthe publication DE-OS 19 20 751 be applied as a part of the method ofthe invention in the sense that, at the start of an induction stroke,the inlet valve and outlet valve are simultaneously open for a while.Thus, a portion of the air filling or the like can be reserved forflushing the cylinder space and this portion is intended to dischargethrough at least one outlet valve. The at least one outlet valve isclosed before the entire air filling is discharged, some of the airfilling remaining in the cylinder space into which a fuel-and-airmixture is passed after the air filling. The air filling or a portionthereof is sucked to above a piston in the cylinder space and thus theexplosive fuel-and-air mixture lies on top of this layer of air. At themoment of explosion, the layer of air on top of a piston in the cylinderspace guarantees a complete combustion and, hence, cleaner exhaustgases.

The method is described in preferred embodiments particularly in termsof engines with two or more cylinders. It should be noted that themethod is applicable to engines operating on either Otto, Diesel orWankel principle.

The present invention relates also to an apparatus for improving theoperation of an engine. In order to achieve the advantages described inconnection with the method, the apparatus is essentially characterizedby comprising means that are synchronized for filling the part of aninlet duct or the like immediately downstream of the inlet valve with anair filling prior to the start of an induction stroke.

An apparatus of the type mentioned before is described in U.S. Pat. No.3,046,960. In such apparatus, a first flap fitted in an inlet duct forair and a second flap fitted in a duct for fuel-and-air mixture areopened and closed by a common actuating lever. However, with theapparatus in accordance with the state of the art, it is not possible toquickly start closing of the first flap at a certain lever position,when such closing is required for the proper functioning of the engine.

The invention will now be described in more detail in the followingspecification with reference made to the accompanying drawings. In thedrawings:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows schematically the basic idea of the invention,

FIGS. 2a-c show the most essential stages of the present method in apiston engine operating on four-stroke principle,

FIGS. 3-5 are views of several embodiments of air filling distributormeans applicable in connection with an engine comprising two or morecylinder spaces,

FIG. 6 is a perspective view of an engine which is equipped with twocylinder spaces and fitted with a distributor means and an adjustmentmechanism (FIG. 6a) for adjusting the air filling in proportion to thespeed of rotation of an engine and

FIG. 7 is a view of the adaptation of a method of the invention to atwo-stroke engine.

FIG. 8 illustrates the opening of a flap as a function of engine speedrotation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

An engine shown in FIG. 1 comprises a cylinder space 1, a piston 2movable therein, an inlet valve 3, an outlet valve 4, an inlet duct 5 aswell as an outlet duct 6. It is obvious that the engine includes normalmechanical elements for controlling the movement of valves and piston aswell as an ignition system with a spark plug 7 as part of it. Thisoverall aspect is not described in detail as it is not a part of thepresent invention and is well known to a person skilled in the art.

According to the basic idea of the present invention, the inlet duct 5is filled with an air filling IT, indicated in FIG. 1 by - signs. Thisair filling starts at the back face 8 of the inlet valve clack andcontinues through a certain adjustable distance in the inlet duct 5.This air filling is followed by a fuel-and-air mixture PAS, indicatedby + signs. According to one aspect of the invention, the forwardportion of air filling or a first portion IT₁ of air filling IT issuingfrom inlet valve 3 can be used for flushing the cylinder space, asdescribed later in more detail. The second portion IT₂ of air filling ITfurther down in inlet duct 5 is adapted to be introduced into cylinderspace 1 only after the outlet valve 4 has closed at the start of aninduction stroke. In any case, the provision of through-flushing isoptional in terms of the invention. Thus, the entire air filling IT canbe introduced into the cylinder space while the outlet valve is closed.

It should be appreciated that the term PAS is intended to cover othercorresponding gases or gas mixtures suitable for the same purpose. Allgas mixtures capable of achieving the characterizing features set forthin the preamble section of this specification can be employed. It isnaturally obvious that such a gas mixture must contain oxygen in acertain proportion.

FIG. 2a illustrates the formation of air filling IT in the inlet duct 5during a power stroke. Thus, air is supplied from a filling duct 9connected with inlet duct 5 through a port 10 between inlet duct 5 andfilling duct 9, which port can be located near inlet valve 3 as shown inFIGS. 2a-c. The air filling IT displaces the fuel-and-air mixture PASaway from the inlet valve further down inlet duct 5, the fuel-and-airmixture having extended all the way to inlet valve 3 after the precedinginduction stroke. Following a power stroke, and especially infour-stroke engines, at the end of an exhaust stroke, whereby the pistonis at or near the top dead center, there will be the situation shown inFIG. 2b. This situation is an overlap situation with inlet valve 3 andoutlet valve 4 simultaneously open for a while, whereby the burnedgases, indicated by circles, discharge into outlet duct 6 as indicatedby an arrow 11. At the same time, while the inlet valve is open, aportion IT₁ of air filling IT discharges from inlet duct 5 into cylinderspace 1 so that this portion exits together with the burned gases intooutlet duct 6.

The situation shown in FIG. 2c is the starting stage of an inductionstroke, with outlet valve 4 having closed and a portion IT₂ of airfilling IT lying on the top surface of piston 2 and, after that, thefuel mixture having filled the rest of cylinder space 1. After theclosing of inlet valve 3 and following a compression stroke, there isagain the situation shown in FIG. 2a after the fuel mixture extending toinlet valve has been displaced to the position shown in FIG. 2a.

At the moment of explosion, in cylinder space 1 on top of piston 2 thereis an air filling IT, either the entire air filling or a portionthereof, as long as the simultaneous opening of inlet valve 3 and outletvalve 4 is employed during an exhaust stroke as indicated in FIG. 2.

It is obvious that in single-piston engines the delivery of air fillingis simple, for example, a control acquired from the rotation of acrankshaft or from the rotation of a member carried thereby can be usedto open a valve communicating with filling duct 9. In addition to thenormal vacuum of an intake manifold, the air filling can in some casesbe obtained by using an air pump or a supercharger.

FIG. 3 shows one way of applying an engine provided with two, four, sixetc. cylinder spaces for practicing the method. Thus, those two (forexample, ST₁ and ST₄) of the cylinder spaces of an engine are alwaysselected, which are simultaneously doing an induction stroke (ST₁) and apower stroke (ST₄). A distributor means 14 provided with two outlets 12and 13 is connected to filling ducts 9₁ and 9₄ communicating withrespective cylinder spaces. The distributor means 14 comprises anelongated chamber space 15, preferably of a circular cross-section, theoutlet connections 12 and 13 as well as an air filling inlet connection16 being in communication therewith. In the chamber space 15 alongitudinally movable clack member 17 is fitted for always closing thatoutlet connection (outlet connection 12 in FIG. 3), whose correspondingcylinder space is in induction stroke. This is due to the fact that atthis point there is a vacuum in the inlet duct that carries clack member17 into alignment with the corresponding outlet connection 12, the clackmember being carried in chamber space 15 by centering springs 17 a, 17b.Thus, from inlet connection 16 there opens through chamber space 15 anaccess to outlet connection 13 and, hence, an air filling IT can developin an inlet duct 5₄. Between the movements of air filling and while theengine is not running, the clack member 17 is in alignment with inletconnection 16 and closes it.

FIG. 4 shows another embodiment of the distributor means.

A distributor means 18 includes a tubular element 19, coupled to berotatable around its longitudinal axis in synchronization with the speedof rotation of an engine by means of a member 20, which is shown asreference. A person skilled in the art is well aware of how to achievesuch synchronization and how to construct member 20, so this is notexplained further in this context. Tube 19 is fitted inside a protectivepipe 21, shown with dash-and-dot lines and provided with communicatingports into filling ducts 9₁ -9₄ connected to cylinder spaces ST₁ -ST₄.Tube 19 is further provided with openings 22, corresponding to thenumber of cylinder spaces and arranged on the periphery of tube 19 insuch a manner that always one opening can be in communication with thefilling connection of one cylinder space. Furthermore, the openings arearranged at regular mutual distances on the outer periphery of tube 19.Thus, as tube 19 is rotating around its longitudinal axis, an air flow(arrow 23), produced by a vacuum prevailing in the intake manifold fordeveloping an air filling IT in an inlet duct connected with eachcylinder space, passes through a corresponding opening 22 into acorresponding filling duct 9₁ -9₄ in a synchronized fashion during thecompression stroke of each cylinder.

FIG. 5 illustrates a still further possible embodiment of an airdistributor. This air distributor 24 comprises a substantially annularframe jacket 25, a distributing disk 26 fitted inside the jacket andprovided with a distributing hole 27. Distributing disk 26 is adapted torotate around an axle 28 which is aligned perpendicularly to the radiusof the annular jacket. The ends of annular jacket 25 are closed on theone hand by an inlet gable 29 and on the other hand by a distributiongable 30. The inlet gable 29 is provided with a filling air inletconnection 31 and the distribution gable 30 is provided with a number ofoutlet connections 32 corresponding to the number of cylinder spaces andcommunicating with filling ducts 9₁ -9₄ and mounted co-radially relativeto the center of distribution gable 30, so that the hole 27 rotating ona circular line with a corresponding radius will be aligned with theoutlet connections. When a vacuum prevailing in the intake manifold isused to supply air into the space of distributor 24 defined by framejacket 25, distributing disk 26 and inlet gable 29 and with hole 27rotating in alignment with inlet gable 30, the air flow always shifts tothat outlet connection 32 which is in alignment with hole 27. Thisoperation is effected in a synchronized fashion.

FIG. 6 is a perspective view of an engine 33 provided with two cylinderspaces. A distributor 24 is similar to that shown in FIG. 5 althoughconstructed to be suitable for two cylinder spaces ST₁ and ST₂. Thefilling ducts 9₁ and 9₂ are mounted in communication with respectiveinlet ducts 5₁ and 5₂ to provide a construction basically similar tothat shown in FIGS. 2a-c. FIG. 6 depicts one of the advantages gained bythe present invention, namely the air filling IT creates in thedistribution duct 34 of inlet ducts 5₁ and 5₂ a reciprocating motionshown by an arrow 35 for further enhancing the mixing of fuel-and-airmixture. The enlarged partial FIG. 6a accompanying FIG. 6 furtherillustrates one embodiment of a mechanism for adjusting the amount ofair filling 36. Fitted in a fuel-and-air mixture inlet duct 37 is afuel-and-air mixture adjustment flap 38 or a similar member. This flapis used to control the speed of rotation of an engine. The adjustmentflap is provided with a leverage 39 for turning the flap around an axisKA extending in the direction of the flap diameter as shown by an arrow40 whenever the operating lever 41 of flap 38, journalled (at 42)rotatably relative to an engine block, is acted upon through theintermediary of a cable 43 or the like. Similarly, a duct 31acommunicating with inlet connection 31 of distributor 24 is fitted withan adjustment flap 44 or the like for adjusting the amount of airfilling. The turning axle 45 of flap 44 or the like is connected by anintermediate spring 46 to the turning axle 47 of flap 38. The turningaxles 45 and 47 are journalled upon sleeves 48 and 49 secured to theengine block. The turning axle 45 of flap 44 is fitted with a leverage50. The extension 41a of an operating lever 41 is adapted to act onleverage 50 as shown by a diagram I. The flap 44 or its turning axle 45is fitted with a cable 53 (53') or the like for keeping flap 44 closedduring a cold start.

FIG. 8 illustrates the opening of a flap as a function of the speed ofrotation of an engine. The diagram shows that flap 38 as the speed ofrotation of an engine increases uniformly and the opening of flap 44 islinked with this opening movement in a manner that, with a cold start ona certain speed range of rotation, flap 44 begins to open after thedetachment of cable 53 and as the intermediate spring 46 transmits theturning of axle 47 to the axle 45 of flap 44. Thus, flap 44 opens to itsmaximum open position as the speed range of an engine is about 40-70% ofits maximum (50% in FIG. 8). After this speed range flap 44 closes veryquickly and remains closed on the top speeds of rotation of an engine.This operation is effected by means of the extension 41a of operatinglever 41 and the leverage 50 of adjustment flap 44 which, upon shiftingsaid operating lever 41 for producing top speed of rotation, encountereach other and this encounter results in the closing of flap 44. Whenoperating lever 41 is returned to its initial position, flap 38 closesand flap 44 remains in its closed position by the action of theintermediate spring. FIG. 8 depicts a corresponding operation also forflaps 38 and 44, so that the relative position of flaps 38 and 44 issketched on respective speed ranges of an engine in alignment withdash-and-dot lines describing ducts 31a and 37. In the example, flap 44forms with the longitudinal axis of duct 31 a 45° angle in its closedposition and flap 38 is perpendicular to the longitudinal axis of duct37 in its closed position. Thus, the turning motion of flap 44 to amaximum position is 45° (closing at half-way point of maximum speed ofrotation) and the turning motion of flap 38 to a maximum position is80°-90°. When the engine is warm, the opening of flap 44 can besynchronized by means of an intermediate spring 46 in direct proportionto the speed of rotation of an engine also on idle run and low speeds ofrotation. This is effected by means of the above adjustment mechanism16. It is obvious that the design of such adjustment mechanism can becaried considerably within the scope of alternative constructionsself-evident for a person skilled in the art. Flap 44 is fully open, forexample, when the speed of rotation of an engine is half of the maximumand it closes when the speed of rotation reaches the maximum. It isclear that the operation of an adjustment flap can also be effected by amanual control which is different from the above operation. In an engineof the present invention, a normal carburator can also be replaced withcontinuous injection or central injection. The engine can also beprovided with a supercharger. It is obvious from the above that theengine can include an even or odd number of cylinders.

FIG. 7 illustrates the application of a method of the invention to atwo-stroke engine. A piston 2 compresses through a crankcase 51 into aninlet duct a mixture of fuel and air. An inlet duct 5 communicates byway of a valve 52 with a filling duct, adapted to operate so as to fillthe forward section of the inlet duct with an air filling IT. The airfilling displaces the fuel-and-air mixture which has arrived in inletduct 5 from crankcase 51. Valve 52 can be a spring-loaded needle valveor the like allowing the flow of air filling IT from filling duct 9 intoinlet duct 5 but not in the opposite direction.

The method and apparatus of the invention are capable of providing anadjustable lean mixture engine. The application of this method requiressufficiently long inlet ducts in an engine so as to reserve a sufficientamount of air in inlet ducts at all operating stages of an engine. Thecover of an engine can be either inclined, semi-spherical, shaped as atrussed roof or a vat. The outlet valve is preferably positioned higherthan the inlet valve and the spark plug at the highest point of acylinder space. A condition for these is of course that the cylinderspace is adapted to extend in vertical direction. The method is capableof providing a reliably running engine which, at the moment ofexplosion, contains a readily ignitable and lean mixture which in turnproduces cleaner exhaust gases and possibly makes even the use of acatalyzer unnecessary. A fuel-and-air mixture received in the engine isuniform with a reciprocating mixing motion developing in inlet ducts 5as well as in their distribution duct (component 35 in FIG. 6). Thus,operation of the carburator and especially a flow therethrough issmooth. In addition, it is possible to employ a higher compression ratioin the engine.

We claim:
 1. A method of improving the operation of an engine, saidengine including a cylinder space, a piston movable therein, at leastone inlet valve having an inlet duct associated therewith, and at leastone outlet valve having an outlet duct associated therewith, said methodcomprising:providing an air filling in said inlet duct upstream of saidinlet valve(s); introducing an initial portion of said air filling intosaid cylinder space while said outlet valve is open whereby said initialportion of air filling flushes said cylinder space and exits into saidoutlet duct through the open outlet valve(s); closing said outletvalve(s) while continuing introduction of said air filling in saidcylinder space; and introducing an air fuel mixture into said cylinderspace through the same inlet duct(s) and inlet valve(s) through whichthe air filling has passed in being introduced into the cylinder,resulting a fuel charge stratified atop of the retained air fillingwherein said air filling is introduced into said inlet duct bydisplacement of said air-fuel mixture within said inlet duct in adirection away from said inlet valve.
 2. A method according to claim 1,wherein said engine comprises at least two cylinder spaces and whereinsaid air filling is being introduced into an inlet duct of each cylinderspace through a communicating filling duct by means of a distributorincluding a control member adapted for passing air filling into eachfilling duct in a synchronized manner.
 3. A method according to claim 2,wherein the operation of said control member is controlled during theinduction stroke of the cylinder space in such a manner that theconnection of cylinder spaces coupled pairwise with the same distributoris closed off, by said control member during each induction stroke foropening a connection to the inlet duct of another cylinder space, inwhich prevails a compression stroke.
 4. A method according to claim 2,wherein the operation of said control member is controlled by means of atransmission obtained mechanically from the speed of rotation of a shaftrotated by said piston of said engine.
 5. A method according to claim 1,wherein the supply of air filling is closed off at a speed of rotationof a shaft rotated by said piston of said engine, which is between 40%and 70% of maximum speed of rotation of said shaft.
 6. A method ofimproving the operation of an engine, said engine including a cylinderspace, a piston movable therein, at least one inlet valve having aninlet duct associated therewith, and at least one outlet valve having anoutlet duct associated therewith, said method comprising:providing anair filling entirely in said inlet duct upstream of said inlet valve(s);introducing said air filling into said cylinder space, at least aportion of said air filling being introduced while said outlet valve isclosed; retaining said at least portion of said air filling in saidcylinder space prior to introduction of an air-fuel mixture; andintroducing an air fuel mixture into said cylinder space through thesame inlet duct(s) and inlet valve(s) through which the air filling haspassed in being introduced into the cylinder, resulting in a fuel chargestratified atop of the retained air filling wherein said air filling isintroduced into said inlet duct by displacement of said air-fuel mixturewithin said inlet duct in a direction away from said inlet valve.
 7. Amethod according to claim 6, wherein air filling is introduced into theinlet duct from a filling duct which connects with said inlet ductsubstantially at the inlet valve.
 8. A method of improving the operationof an engine, said engine including a cylinder space, a piston movabletherein, at least one inlet valve having an inlet duct associatedtherewith, and at least one outlet valve having an outlet ductassociated therewith, said method comprising:providing an air filling insaid inlet duct upstream of said inlet valve(s); introducing an initialportion of said air filling into said cylinder space while said outletvalve is open whereby said initial portion of air filling flushes saidcylinder space and exits into said outlet duct through the open outletvalve(s); closing said outlet valve(s) while continuing introduction ofsaid air filling in said cylinder space; and introducing an air fuelmixture into said cylinder space through the same inlet duct(s) andinlet valve(s) through which the air filling has passed in beingintroduced into the cylinder, resulting in a fuel charge stratified atopof the retained air filling, wherein said engine comprises at least twocylinder spaces and wherein said air filling is being introduced into aninlet duct of each cylinder space through a communicating filling ductby means of a distributor including a control member adapted for passingair filling into each filling duct in a synchronized manner; and whereinthe flow of air filling into said inlet duct is controlled by anadjustment means, said adjustment means including a first regulatingmember fitted in a duct communicating with an inlet connection of saiddistributor; a second regulating member fitted in an upstream portion ofsaid inlet duct, and means operatively interconnecting said first andsecond regulating members and being adapted for transmitting movement ofsaid second regulating member to said first regulating member, wherebyadjusting effect imparted upon said second regulating member istransferred as a corresponding adjusting effect to said first regulatingmember.
 9. A method according to claim 8, wherein said first regulatingmember is closed at a rotational speed of a shaft rotated by said pistonof said engine which is between 40% and 70% of maximum speed of rotationof said shaft.
 10. A method according to claim 8 further comprisingmeans for holding said first regulating member closed during a coldstart.
 11. An apparatus for improving the operation of an engine, saidengine including at least two cylinder spaces, each cylinder spacecomprising a piston, at least one inlet valve, at least one outletvalve, an inlet duct for fuel-and-air mixture associated with said inletvalve, and an outlet duct for burned gases associated with said outletvalve, said apparatus also including an air introducing means forfilling a section of said inlet duct immediately upstream of said inletvalve with an air filling prior to the start of an induction stroke,said air introducing means comprising:a filling duct for each saidcylinder space, each respective filling duct being connectable to saidrespective inlet duct at said respective inlet valve; said filling ductsbeing in communication with a distributor adapted for introducing saidair filling into said filling ducts in a manner synchronized with theoperation of said engine; adjusting means for controlling the amount ofthe air filling, said adjusting means being operatively connected withsaid distributor, and including a first regulating member fitted in aduct communicating with an inlet connection of said distributor, asecond regulating member fitted in an upstream portion of said inletduct, and means operatively interconnecting said first and secondregulating members, said interconnecting means being adapted fortransmitting movement of said second regulating member to said firstregulating member, whereby adjusting effect imparted upon said secondregulating member is transferred as a corresponding adjusting effect tosaid first regulating member.
 12. An apparatus for improving theoperation of an engine, said engine including at least two cylinderspaces each cylinder space comprising a piston, at least one inletvalve, at least one outlet valve, an inlet duct for fuel-and-air mixtureassociated with said inlet valve and an outlet duct for burned gasesassociated with said outlet valve, said apparatus also including an airintroducing means for filling a section of said inlet duct immediatelyupstream of said inlet valve with an air filling prior to the start ofan induction stroke, said air introducing means comprising:a fillingduct for each said cylinder space, each respective filling duct beingconnectable to said respective inlet duct for fuel-and-air mixture atsaid respective inlet valve; said filling ducts being in communicationwith a distributor adapted for introducing said air filling into saidfilling ducts in a manner synchronized with the operation of saidengine; means for adjusting the amount of the air filling operativelyconnected with said distributor, said adjusting means including a firstregulating member fitted in a duct communicating with an inletconnection of said distributor; a second regulating member fitted in anupstream portion of said inlet duct; and means for connecting said firstand second regulating member and adapted for controlling movement ofsaid first regulating member according to the movements of said secondregulating member; said connecting means including an intermediatespring for linking the axis of said first and second regulating memberand an operating lever, said operating lever being acted upon by meansof a cable or the like for imparting the adjusting effect to said secondregulating member, a substantially parallel effect or action beingtransmitted to the first regulating member by means of said intermediatespring; wherein in a certain operating lever position, a member of saidoperating lever is adapted to shift said first regulating member quicklyback to a closing position against the force of said intermediatespring.
 13. An apparatus according to claim 12, wherein said firstregulating member is provided with a closing member for retaining saidfirst regulating member in a closed position during a cold start.
 14. Anapparatus according to claim 12, wherein said cylinder spaces arepairwise coupled with a common distributor, said distributor beingprovided with two outlets connected to said filling ducts, a chamberspace and a control member movable therein, said control member beingadapted through the vacuum resulting from the induction stroke toalternately close outlets for supplying air filling from thedistributor's inlet connection through the opened outlet of said chamberspace into the inlet duct of that cylinder space wherein prevails acompression stroke.
 15. An apparatus according to claim 12, wherein saiddistributor includes a tubular member rotatable around its longitudinalaxis by rotating means according to the speed of rotation of the engine,a protective pipe which is provided with connecting ports leading intosaid filling ducts and which surrounds said tubular member and openingswhose number corresponds to that of said cylinder spaces and which aredistributed in said tubular member in such a manner that at least one ofsaid openings at a time, is in communication with a correspondingconnecting port in a manner synchronized with the operation of theengine.
 16. An apparatus according to claim 12, wherein said distributorcomprises a distributing disk provided with a distributing hole andadapted to rotate between an inlet end and an outlet end so as to open acommunication path to each outlet connection associated with the outletend and leading to a respective filling duct, said communication pathopening alternately to each outlet connection from an inlet connectionat said inlet end.